The first day I got this thing and put it on the car visor and drove to work I started hearing a rattling noise which I thought was coming from my car. Upon further inspection I found that it was the metal on metal contact between the visor clip and the magnetic portion of the unit. I exchanged it for another one and its not as noticeable but its still there. Calling tech support for this product is useless. The tech support guy for Dual seemed rather annoyed that I was calling and gave one word answers.